Also known as Potential failure modes and effects analysis, Failure modes, Effects, and Criticality Analysis (FMEA) in Six Sigma.

FMEA was established in the 1940s by the U.S. Military. It is a step-by-step approach to identifying any failures in a design or manufacturing process or product or service. It is a common tool for process analysis.

  • “Failure mode” refers to the possible failures of something. Any errors or defects that are not in the best interest of the customer and especially if they affect them, are called failures.
  • “Effects Analysis” is the study of the consequences of these failures.

Prioritization is based on the severity of failures, their frequency, and how easily they can be detected. FMEA’s purpose is to identify and eliminate failures.

Failure modes and effects analysis document current knowledge and actions regarding the risk of failures. This information can be used to improve continuously. FMEA is used to prevent failures during design. It’s also used to control the process, both before and after it is completed. FMEA should be initiated during the initial stages of product design and continue throughout the service or product’s life.

Six Sigma FMEA Process

  • After quality function deployment, a process, product, or service can be designed or redesigned.
  • A process, product, or service that is already in use, can be applied in a different way.
  • Before you develop control plans for a new process or modification,
  • If improvement goals are set for a product, process, or service,
  • Analyzing failures in a product, process, or service is a way to identify them.
  • Throughout the entire lifecycle of the product, process, or service, it is recommended to review the status periodically.

Six Sigma FMEA Example

FMEA was performed by a bank on their ATM system. It includes the function “dispense Cash” as well as some of the failure modes. The optional column “Classification” was not used. The headings for the rightmost column (action) are not shown.

It is important to note that RPN (and criticality) prioritize different causes. RPN states that “machine jams”, and “heavy network traffic” are the most dangerous.

A high RPN is generated by a detection rating of 10, which has a 10 for severity and occurrence times. The detection rating does not count in criticality. Therefore, it rates highest the cause with the highest severity or occurrence value: “out of cash”. To determine the best priorities of action, the team should use their knowledge and judgment.